TURBOCHARGER

Abstract

The invention relates to a turbocharger (1) provided with a turbine housing (2) for turbine wheels, a cartridge (K) for the variable turbine geometry positioned in the turbine housing (2), a bearing housing (3) which is arranged between said turbine housing (2) and a compressor housing of the compressor wheel and in which a bearing arrangement for a shaft (W) carrying the turbine and compressor wheels is mounted and a pane system (4) placed between the cartridge (K) and the bearing housing (3). The inventive turbocharger is characterized in that said pane system (4) consists of at least two material layers (5,6), an air gap (7) is formed between the material layers (5,6), the material layer (5) is embodied in the form of a conical plate and the other material layer (6) is provided with a bend (8).

Full Text

WO 2006/133793 PCT/EP2006/004905
Turbocharger
Description
The invention relates to a turbocharger according to the
preamble of claim 1.
Such a turbocharger is known from EP 1 398 463 A1 . In
this turbocharger, a heat shield is provided around its
shaft on the turbine side and serves to protect the
bearing housing from damage due to elevated temperatures
on account of the exhaust gases of the internal
combustion engine which flow through the turbine. The
known heat shield consists of a single-layer component,
the heat insulation properties of which, however, are in
need of improvement.
A further arrangement is shown in EP 0 160 460 B1, a disk
spring being used here which exerts an axial preloading
force on the vane ; ring to be fixed axially. The
functioning of the heat insulation is not necessary on
account of the remoteness of the turbine wheel at this
point.
It is therefore the object of the present invention to
provide a turbocharger of the type specified in the
preamble of claim 1 which firstly ensures axial fixing of
the cartridge of the variable turbine geometry in the
vicinity of the turbine wheel by means of a disk spring
and secondly permits improved heat insulation in the
direction of the bearing housing via the heat shield.
This object is achieved by the features of claim 1.

WO 2006/133793 - 2 - PCT/EP2006/004905
The disk arrangement of the turbocharger according to the
invention is formed from at least two material layers,
but if need be from a plurality of material layers, and
includes both the function of producing the preloading
force and the improvement of the screening function by
increasing the heat resistance. As a result, it is
possible to ensure the functioning, especially at
increased exhaust gas temperatures.
In addition, liquid cooling of the bearing housing can
possibly be advantageously dispensed with.
Due to the provision of a plurality of material layers,
it becomes possible to provide an air gap between the
material layers in order to further improve the
preloading force properties and/or the heat insulation
properties.
To this end, one of the material layers is provided with
a bend which provides two regions arranged at a
preferably obtuse angle to one another, while the other
material layer is designed as a disk in accordance with a
Belleville spring.
The subclaims concern advantageous developments of the
invention.
The material layers form two separate parts, preferably
shaped plates, which rest one on top of the other in the
region of their outside diameter.
Furthermore, it is in principle possible for the material
layers to be made of the same material or for different
materials to be selected.

WO 2006/133793 - 3 - PCT/EP2006/004905
In claim 10, a disk arrangement for a turbocharger
according to the invention is defined as object which can
be sold separately.
Further details, advantages and features of the present
invention follow from the description below with
reference to the drawing, in which:
fig. 1 shows part of a turbocharger according to the
invention with a disk arrangement according to the
invention, and
fig. 2 shows an enlarged illustration of the disk
arrangement according to the invention.
A section of a turbocharger 1 according to the invention
is shown in fig. 1, since this illustration is sufficient
for the explanation of the principles according to the
invention. Of course, the turbocharger 1 has all the
constructional elements normally provided, which,
however, as stated, are omitted in fig. 1 in order to
simplify the illustration.
Therefore a turbine housing 2 of a turbine is shown in
fig. 1, said turbine housing 2 being arranged adjacent to
a bearing housing 3. This bearing housing 3 is arranged
between the turbine housing 2 and a compressor housing
(not shown) of a compressor wheel (likewise not
depicted) . The bearing housing 3 has the bearing for a
shaft, which in fig. 1 is symbolized by the dot-dash
center line M, since fig. 1 only reproduces the top
section of the turbocharger 1 according to the invention.
The shaft W carries the turbine and the compressor wheel

WO 2006/133793 - 4 - PCT/EP2006/004905
and is mounted in the bearing housing 3 via a suitable
bearing arrangement.
A disk arrangement 4 of multi-layer design is clamped in
place between the bearing housing 3 and a cartridge K
which is formed by a VTG disk 12 having an axial stop 14
and a vane ring 15 and is arranged in the turbine housing
2 in an axially displaceable manner. Here, in the
example, there are two material layers 5 and 6, which are
explained in more detail below with reference to fig. 2.
Fig. 1 illustrates the disk arrangement 4 between the
turbine housing 2 and the bearing housing 3, two
supporting regions 10, 11 being obtained, with which the
material layer or disk spring 5, as can be seen in detail
from fig. 1, is supported on the corresponding parts of
the vane ring of the cartridge of the variable turbine
geometry of the bearing housing 3.
The material layer or the inner heat shield 6 is clamped
in place at the outside diameter by the disk spring 5
relative to the vane ring 15.
An embodiment of the disk arrangement 4 according to the
invention is shown in fig. 2. In this embodiment, the two
material layers 5 and 6 are of two-piece design. Fig. 2
illustrates that the material layer or disk spring 5,
which applies the axial preloading force, has a conical
configuration. Furthermore, the material layer 5 has a
center aperture 16, which is arranged coaxially to a
center aperture 17 of the material layer 6, serving as
heat shield for the material layer 5, and has an equally
large diameter. Provided between the material layers 5
and 6 is an air gap 7, which further improves the heat
insulation properties. This air gap 7 is achieved by the

WO 2006/133793 - 5 - PCT/EP2006/004905
provision of a bend 8 in the heat shield 6, which divides
the latter into two regions 9, 9' , which are preferably
arranged at an obtuse angle to one another.

WO 2006/133793 - 7 - PCT/EP2006/004905
Claims
1. Turbocharger (1)
- having a turbine housing (2) of a turbine wheel;
- having a cartridge (K) arranged in the turbine
housing (2) for the variable turbine geometry;
- having a bearing housing (3) which is arranged
between the turbine housing (2) and a compressor
housing of a compressor wheel and in which a bearing
arrangement for a shaft (W) carrying the turbine
wheel and the compressor wheel is arranged; and
- having a disk arrangement (4) which is arranged
between the cartridge (K) and the bearing housing
(3);
characterized in that
- the disk arrangement (4) is composed of at least two
material layers (5, 6),
- an air gap (7) is arranged between the material
layers (5, 6) ,
- the one material layer (5) is designed as a conical
disk, and
- the other material layer (6) is provided with a bend
(8) .
2. The turbocharger as claimed in claim 1,
characterized in that the material layers (5, 6) have
center apertures (16 and 17 resp.) having the same
diameter.
3. The turbocharger as claimed in claim 1 or 2,
characterized in that the material layers (5, 6) have the
same diameter.
4. The turbocharger as claimed in one of claims 1 to 3,
characterized in that only the conical material layer (5)

WO 2006/133793 - 8 - PCT/EP2006/004905
abuts at its the inside diameter against the bearing
housing (3) .
5. The turbocharger as claimed in one of claims 1 to 4,
characterized in that the material layers (5, 6) are
separate parts.
6. The turbocharger as claimed in one of claims 1 to 5,
characterized in that the material layer (6) is axially
restrained in the region of its outside diameter by the
material layer (5).
7. The turbocharger as claimed in one of claims 1 to 6,
characterized in that the material layers (5, 6) are made
of the same material.
8. The turbocharger as claimed in one of claims 1 to 6,
characterized in that the material layers (5, 6) are made
of different materials.
9. The turbocharger as claimed in one of claims 1 to 8,
characterized in that the material layer (6) provided
with a bend constitutes a thermal insulation or an inner
heat shield for the other material layer (5) forming an
outer disk spring.
10. A disk arrangement (4) for a turbocharger (1)
according to the preamble of claim 1, characterized by at
least one of the characterizing features of claims 1 to
3.

The invention relates to a turbocharger (1) provided with a turbine housing (2) for
turbine wheels, a cartridge (K) for the variable turbine geometry positioned in the
turbine housing (2), a bearing housing (3) which is arranged between said turbine
housing (2) and a compressor housing of the compressor wheel and in which a bearing
arrangement for a shaft (W) carrying the turbine and compressor wheels is mounted
and a pane system (4) placed between the cartridge (K) and the bearing housing (3).
The inventive turbocharger is characterized in that said pane system (4) consists of at
least two material layers (5,6), an air gap (7) is formed between the material layers
(5,6), the material layer (5) is embodied in the form of a conical plate and the other
material layer (6) is provided with a bend (8).